gStore/VSTree/VSTree.h

109 lines
4.2 KiB
C++

/*=============================================================================
# Filename: VSTree.h
# Author: Bookug Lobert
# Mail: 1181955272@qq.com
# Last Modified: 2015-11-01 13:02
# Description: originally written by liyouhuan, modified by zengli
=============================================================================*/
#ifndef _VSTREE_VSTREE_H
#define _VSTREE_VSTREE_H
#include "../Util/Util.h"
#include "../Query/SPARQLquery.h"
#include "VNode.h"
#include "LRUCache.h"
#include "EntryBuffer.h"
//NOTICE:R/W more than 4G
class VSTree
{
friend class VNode;
public:
VSTree(std::string _store_path);
~VSTree();
int getHeight()const;
//build the VSTree from the _entity_signature_file.
bool buildTree(std::string _entity_signature_file);
bool deleteTree();
//Incrementally update bitset of _entity_id conduct OR operation on Entry(_entity_id)'s EntityBitSet with _bitset
//Entry of _entity_id must exists
bool updateEntry(int _entity_id, const EntityBitSet& _bitset);
//Replace the Entry(_enitty_id)'s EntityBitSet with _bitset Entry of _entity_id must exists
bool replaceEntry(int _entity_id, const EntityBitSet& _bitset);
//insert an new Entry, whose entity doesn't exist before
bool insertEntry(const SigEntry& _entry);
//remove an existed Entry(_entity_id) from VSTree
bool removeEntry(int _entity_id);
//save the tree information to tree_info_file_path, and flush the tree nodes in memory to tree_node_file_path.
bool saveTree();
//load tree from tree_info_file_path and tree_node_file_path files.
bool loadTree();
//get the tree's root node pointer.
VNode* getRoot();
//get the node pointer by its file line.
VNode* getNode(int _line);
//retrieve candidate result set by the var_sig in the _query.
void retrieve(SPARQLquery& _query);
//retrieve the candidate entity ID which signature can cover the_entity_bit_set, and add them to the _p_id_list.
void retrieveEntity(const EntityBitSet& _entity_bit_set, IDList* _p_id_list);
private:
int root_file_line;
int node_num;
int entry_num;
int height;
LRUCache* node_buffer;
EntryBuffer* entry_buffer;
map<int, int> entityID2FileLineMap; // record the mapping from entityID to their node's file line.
static std::string tree_file_foler_path;
static std::string tree_node_file_path;
static std::string tree_info_file_path;
//manage the node id to deal with insert/delete(only when node is created or removed).
//To create node, if free list is empty, then max_nid_alloc++;else, get one from free list
//To remove node, add its ID to free list
std::list<int> free_nid_list;
//max_nid_alloc-1 is the maxium using ID(need to maintain)
int max_nid_alloc;
//choose the best leaf node to insert the _entry, return the choosed leaf node's pointer.
VNode* chooseNode(VNode* _p_node, const SigEntry& _entry);
//split the _p_full_node to two new node when it is full.
//the parameter _insert_entry and _p_insert_node are the entry/node
//need to be insert to the _p_full_node.
void split(VNode* _p_full_node, const SigEntry& _insert_entry, VNode* _p_insert_node);
//deal when _child key num not enough
void coalesce(VNode* _child, int _entry_index);
//create a new node when one node need splitting.
VNode* createNode();
//swap two nodes' file line, their related nodes(father and children nodes) will also be updated.
void swapNodeFileLine(VNode* _p_node_a, VNode* _p_node_b);
//save VSTree's information to tree_info_file_path, such as node_num, entry_num, height, etc.
bool saveTreeInfo();
//load VSTree's information from tree_info_file_path.
bool loadTreeInfo();
//traverse the tree_node_file_path file, load the mapping from entity id to file line.
bool loadEntityID2FileLineMap();
//update the entityID2FileLineMap with the _p_node's child entries, the _p_node should be leaf node.
void updateEntityID2FileLineMap(VNode* _p_node);
//get the leaf node pointer by the given _entityID
VNode* getLeafNodeByEntityID(int _entityID);
//delete node and update the LRUCache and file storage
void removeNode(VNode* _vp);
std::string to_str();
};
#endif // _VSTREE_VSTREE_H